Thread lock



July 13 1926. 1,592,435

R. E. PIERCE ET AL THREAD LOCK Original. Filed Feb. 16, 1924 Fatented July 13, 1926.

Uni sTAjfr 1 rafraivrlePrice. I

ROBERT E. PIERCILOF ST. LOUIS, TJIISSOURI, AND FREDA. WEL'I'S, BRC'OKLYN,4 NEW YORK; ASSGNORS TO BEMIS F MISSOURI.

BRO. BAG CO.,KOF ST. LOUISQMISSOURI, A CORPORATON i THREAD Loox;

Application mea February 1G, 1924, seriaiivo. 693,180. iten'ewedviviay e, 192e.`

Uur inventionl relates .to improvements in thread locks, and has for its primary object a thread'locky which is operated intermittently and iduring certain" periods of the movementor` the needlel bar so that the needle threadwill' be locked against feeding.

irturther object is `to'coiistruct a needle thread lock whichE is operated intermittently by the movementof the needle bar operating mechanism.V y l Aestil'l further object is'to rconstruct a needle Ithread lock-Whichcan be readily adjusted so as to accommodate various sizes o1 thread.' i

In the'drawings,

Fig. 1 is a` fragmental view of a sewing j machine head fvvitli our device in position. Fig. 2 is la ragmental top plan view of the same.`

3 is an enlarged Section taken on the line 3-3'ot' Figashowing the vtension and its operatingmechanism in position.

Fig. Llis-an enlarged 'aceview of our device with' the tensioni mechanism removed.

Fig. 5 is a side view of a cross head eniplo'yedi Fig. 16 'isa top planview of saine. Fig.y 7 is a view of the lcross head stud. Fig. 8 is a front elevation or' the tighteningl ymember. K A

Figa@ is a tragmental view ot' a .sewing machinehead showing' a modilied 'forni ot tlireadjlock.

Figi'l() is a facelviewof `modified form' of tightening member.

Fig. 11 isa face view ofthe connecting linkl employed inthe-modified form, and

Fig. 12 is an edge view'of the same. Iii-the :construction of -our device, We einploy-asewingfniachine having a head' 15. Mounted inthis head 'is the usual needle bar 16.1 i This needle bar is'iiioved` up 4and 'down byrineans offa lever1l7.'l Thelever 17 vis preferably pi'votal-lysecured (to the head 15 at a point indicated by the-numeral '18.' The lever 17 is rocked fon thepivot 18 by means of Aa connection-195'" which connection is securedl to the dri-'vingmechan ismAV (not shown) f inthe usual manner.A The head lpis pro#r videdV `with a lpan Ntensi-oii20 and with 'thread guides12f1i'ai'idi y22,.- while lever 17 jis; provided Y the .opening and `into which the screw threaded end=33 or' the stud passes.

llocated on the screw threaded end 33 oit thestud and between .the housing 24 vand bracket 31 is a-knurled thumb Wheel r311-, the purposeof which is `to feedl the stud back# ward and torwardthrough the ihousingl.y

Formed integral withthe `enlargement 28 and on` tliepopposite'side of the screw threaded :portionl 33 is a second threaded portion This portion is provided with a ynmltiple screw thread -or helix iso as toV have arather coarse lead'.y It will be noted froml Fig. 3 that the helix does not extend completely to thefenlargenient 28,l leaving a v cylindrical portion 36-and on this cylindrical portionis mounted a washer 37 which is provided with a central recess 38. Placed againsttlie washer-37 iS a paii tension 39. Mountedon the helix lis a tightening-mem- Vrber 40,r which is provided' with internal grooves or screw threads to receive the threads Yformed on thev projection 35. The tightening member -v has formed integral therewith an arm 4:1, whicliis bifurcated on its-'end 'asindicatedat 42. Each arm of they bifurcation is'provided -withxapad 43 which pad is fornishing purposes. Slidably located'inthe bifurcation 42 is a cross head 44,'

whichlis provided witli'a central openingl.

.This opening is adapted to receive the cylindrical portion ltifottheacross head Stud.'y Adjacent'ftol cylindrical 'portion lfiof thev cross head stud visan integral collar 47 and adjacent `this jeollar is a screwl thread portionAB, which isl adaptedf'to be extended through the` lever- 17 'and-secured 'thereto by" meansetfthe nut 495l This arrangement willAVV allow the tightening .nieinberf when rocked by `the lever-`17fto travel backward 'and tor-A 'Wardofn the helix',andallo-wthe cross head: to 4Islide'finir-1the cylindricaliportion-'fe with:

(i5 provided with anopening 32 concentric with out imparting any twisting movement to the helix 35. ln Fie'. i) we have shown a motn lied form in which the tightening member si) is equipped with au integral extensionwt) which is provided adjacent its :tree end with an opening 5l. The iree end of the extension i0 is placed 'within the hiturcationn52l ot the connecting link rlhe bifurcation 52 is adapted to receive a pin 51k which extends con'ipletely therethrough and also through the opening l, thus pivotally connecting the extension 50 and linlr The lower end oilE the iinlr is provided with an opening- 55 which is adapted to be slipped over the c v/.f'lindrical portion 5G of the Cross head stud. n j

The operation of our device is as follows:

ritter the device has been assembled as ies. l and 9 the movement of the lever L es the tightening member i0 on the A. causing it to travel to and from the housing 2e. rl`his movement ofthe tightening inen'iher alternately presses the pans 39 thwards each other and releases them periodically, thus exerting a locking and releasing action on the thread which passes between the tensions, this thread having heen previously passed through the thread guide 21, the pan tension Q0, the thread guides and 23 and the intermittent tension or lock and so on to the needle. rllhe degree of tension or locking imparted to the thread by our device is regulated in the following manner: rlie screvv 2T is loosened and Ythe thumb wheel 3st is rotated ng the enlargement QS baclrwardor lforward in the opening ot the housing. T his lmcl-ward or forward moven'ient carries with it the tightening member and consequently allows either a greater or lesser degree of tension to be placed upon the thread between the inns 39 as desired or permits th insertion ot :iy thicker thread and due to the fact that the. stud is held against rotation hy means o l the lreyway 29 and pin 30, the same amount oi' backward or forward movement as well as the period of time or" such movements remains constant. This would not be the case were the stud permitted to turn in the housing because the position of the helix would then constantly change and consequently the effect of the tightening men'iher be varied accordingly. After the proper adjustment has been made the screw 2T tightened securely hinding the enlargement 2S.

The purpose of this binding is to prevent any accidental rot-ation of the thumb wheel Si due to vibration of the machine. In the modification as shown the link 53 takes the place ot the cross head and may be found desirable, under certain conditions. It being understood, or" course, that we do not desire to inuit ourselves tothe precise C011,-

struction of the device as shown; because there are numerous machines on the market to which our device may he attached which encanto 'the needle bar in a ditl'erent manis used. ior instance, to close the lock or the length of time during remains closed will vary in speed of the other moving wiarts ot' the machine, the loch remaining open a continually increasing length of time as the machine increases in speed, due to the 'nertia of the resilient means and the movi part-s of the loclr. in fact it would he possible to run a machine at such a high rate et speed that thc loclr would not close at all. VThis condition would be impossible in applicants device because as aforementioned both n'iovements of the lock are positively driven hy the needle bar operating mechanism. Furthermore, it a resilient n'zoan used it will crystallize in a short time aud'become useless, due to the rapidity of expansion and contraction imparted i0 lo.

Having 'fully described our invention, what we claim is:

l.. A thread lock comprising in combina tion with a sewing machine head, its needle har and needle bar operating mechanism. a housing secured to said head, a stud slidably mounted in said housing, a helix formed on said stud, a pan tension mounted on said stud adjacent the housing, and neans mounted on the helix and operated by the needle bar operating means for alternately exerting and releasing pressure at predetermined intervals on said pan tension, whereby a thread passing between the pan tension is alternately locked and released during the movement of the needle bar.

2. A thread lock comprising in combina tion with Va sewing machine head, its needle bar and needle bar operating means oi a housing secured to said head, a stud slidably mounted in said housing, means for slidahlv adjusting and projecting beyond said stud in said housing, a helix formed on said stud beyond the housing.

rer.- teiS-ieas eel-fied 1u Said Stud adjacent.

than shown, but to which our device ein tightening member is moved to and fromv said pan tension during the rocking of the needle bar operating means and means carried by the housing for securely locking the "inst-mentioned stud in adjustedvposition.

3. A thread lock comprising in combination with a sewing machine head having a needle bar and a needle bar operating mechanism, of a housing mounted on said head, a stud slidably mounted in said housing, means carried by said housing for preventing said stud from turning, means carried by the stud for adjusting the same laterally through said housing, means carried by the housing for locking the stud in adjusted position, a helix formed on the stud, a tightening member mounted onl said helix, pan tensions carried by the stud between the tightening member and the housing, a bifurcated arm carried by said tightening member, a crosshead located-in said bifurcation, and a stud carried by the needle bar operating mechanism, said stud extending through the crosshead whereby the tightening member is oscillated on the helix and moved to and from said pan tensions thus increasing and diminishing the tensionv at predetermined positions of the needle bar whereby a thread passing through said tensionmay be periodically held against movement therethrough.

4. A thread lock comprising a housing, a stud adjustably carried thereby, a helix formed on said stud, a tightening member mounted on said helix, said tightening member adapted to be rocked on said helix by the needle bar operating mechanism whereby the same is moved to and from said housing, and a pan tension mounted'on the stud ybetween the housing and tightening member, said pan tension adapted to be tightened and loosened alternatelyby movement of the tightening member on the helix.

5. A thread lock comprising a housing, a stud Y adjustably carried thereby, a helix formed on said stud, a tightening member mounted on said helix, pan tensions mount-` ed on said stud between the tightening mem-` ber and housing, said pan tensions adapted to be moved to and from eachother when the tightening member is rocked on the helix, and means securedy to the needle bar operating mechanism ot" a sewing machine Yfor alternately operating the tightening member to andfrom the pan tension.

6. V'lhethread lockk of claim 4 in which the stud is provided with means whereby Athe same can be adjusted kin the housing for regulating the pressureexerted by the pan tensions on the thread.

' 7,. The thread lock of claim 5 in which the housing is provided with means whereby the stud can be locked in adjusted position.

8. A thread lock comprising a housing, a stud adjustably Vcarried thereby, a helix formed on vsaid stud, a tightening member` mounted on said helix, pan tensions mounted on the stud between the housing and tightening member, and means carried by the tightening member and operated by the needle bar mechanism of a sewing machine whereby saidtightenmg member may be rocked on said helix'for moving the 'saine n to and from the vhousing kand the pressure ofthe pan tensions on ya thread be alternately increased and released thereby.

In testimony whereof, we have signed our names to this specilication.

ROBERT n. rmncn' 'FRED A. wnL'rs. 

